Synthesis and characterization of folic acid-conjugated chitosan nanoparticles as a tumor-targeted drug carrier

Objective To synthesize and characterize paclitaxel (PTX)-loaded folate-conjugated chitosan (FA-CTS/PTX) nanoparticles and evaluate its cytotoxicity in vitro. Methods CTS/PTX and FA-CTS/PTX nanoparticles were prepared using reductive amidation and ionic gelation of chitosan with tripolyphosphate anions (TPP). The particle size was determined by laser scattering and the morphology observed using transmission electron microscopy, and the PTX content in the nanoparticles was determined using ultraviolet spectrophotometer at 227 nm. The in vitro cytotoxicity of the nanoparticles against HeLa cells was evaluated by MTT assay. Fluorescence microscopy was used to observe the HeLa cells incubated with FA-chitosan nanoparticles in the presence or absence of folic acid in the culture medium. Results PTX loading did not cause adhesion of the FA-CTS nanoparticles, which presented with uniform spherical morphology with an average diameter of 282.8 nm. The loading and encapsulation efficiencies of FA-CTS/PTX were 9.0% and 75.4% , respectively. The FA-CTS nanoparticles showed a greater extent of intracellular uptake in the absence of folic acid, indicating that the cellular uptake of the nanoparticles occurred through endocytosis mediated by the folate receptors. The PTX-loaded FA-CTS nanoparticles exhibited potent cytotoxicity against HeLa cells, an effect 2- to 3-fold stronger than that of PTX-loaded CTS nanoparticles. Conclusion FA-CTS can be a promising drug carrier with high efficiency in condensing drug, good tumor-targeting ability and low cytotoxicity.